Quality and accountability remain meaningful discussions for university-based traditional educator preparation programs (EPPs) that prepare most new teachers. A fundamental premise of this study is to create rigorous and transparent measures that are intentionally designed and aligned with pre-service teacher (PST) readiness standards, which is one attempt to define teaching effectiveness and, by extension, teacher quality. These measures will consider two critical perspectives of readiness to teach: PST self-efficacy of their readiness teach and observed PST readiness from the perspectives of experts. This study examined the methodology of aligning self-reported and observational data to create a system of instrument. To accomplish this, a multi-phased, methodological approach was established that integrated measurement, statistical, and qualitative methods to investigate the validity of a self-report questionnaire and an observational instrument, guided by the Messick (1995) and Wolfe and Smith (2007a, 2007b) frameworks. This approach can be replicated by any EPP looking to improve their instrument practices of professional readiness to teach, or any other industry with professional standards. For this study, 36 PSTs completed the initial Professional Readiness to Teach Inventory and 37 PSTs completed the revised version. Five University Field Supervisors (UFSs) completed the observation for 34 PSTs during the same semester. The revised instruments (self-reported and observed) were based on the initial instrument utilized by the college to provide evidence for accreditation of the PSTs' ability to meet professional standards. Overall, the construct of professional readiness to teach was defined differently through the self-reported and the observed data. PSTs and UFSs did not show agreement on most of the items in terms of difficulty to endorse. Therefore, there was no significant linear relationship found between the two instruments. However, both instruments were able to classify the PSTs level of readiness similarly. Future research should analyze the functionality of the raters within the assessment system. Additionally, future studies could provide further insight into effective strategies to mitigate the impact of social desirability and hesitancy to provide negative feedback. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]